(WRIC/ABC) — A breakthrough technology has sparked some hope to a family who thought their baby girl might not make it to her second birthday.

At just 14-weeks-old Layla Richards was diagnosed with leukemia last year, according to the Great Ormond Street Hospital in London. Her doctors tried multiple treatments for the girl, including a bone marrow transplant, though nothing worked.

Just after her first birthday, doctors suggested Layla’s family consider palliative care.

“We didn’t want to accept palliative care and give up on our daughter, though, so we asked the doctors to try anything,” Lisa Richards said on the hospital website.

Hospital officials then offered the family a shot at an experimental treatment that had only ever been tried before with mice. The medical staff would retrain donated T-cells, which help fight off infection in the body, in hopes that they would attack her cancer. Using these kinds of “edited” T-cells from a donor had never been tried before.

Dr. Waseem Qasim, professor of cell and gene therapy at University College of London’s Institute of Child Health , worked with the family and helped design treatment for Layla. Because the baby didn’t have enough T-cells of her own to be modified with genetic material, doctors had to use donated cells.

Using tools that act like genetic “scissors,” the doctors were able to cut genes from the modified donor T-cells so that they would not attack her and cause a dangerous “graft vs. host” condition, ABC News reports. They used the same tools to add synthetic genetic material that made the cells go after the cancer.

“The approach was looking incredibly successful in laboratory studies, and so when I heard there were no options left for treating this child’s disease, I thought, ‘Why don’t we use the new [modified T-cells]?” Qasim said on the hospital website.

Once prepared, it was as simple as giving Layla an injection. While a severe immune response was possible, the baby only developed a rash.

Weeks later, doctors called in Lisa Richards and gave her the results.

“I thought it was bad news but then he said, ‘It’s worked’ and I just cried happy tears,” Lisa Richards said on the hospital website.

Layla went into remission and eventually had a second bone marrow transplant to strengthen her immune system. She’s now home with her family and seems to be healthy.

Layla’s doctors are excited by her progress but said they need to replicate the findings.

“We have only used this treatment on one very strong little girl, and we have to be cautious about claiming that this will be a suitable treatment option for all children,” Dr. Qasim said. “But this is a landmark in the use of new gene engineering technology and the effects for this child have been staggering.

“If replicated, it could represent a huge step forward in treating leukemia and other cancers.”

Experts say this case could be the start of a new frontier in fighting cancer. While similar treatments called immunotherapy are being studied globally, this is the first case where a donor T-cell was modified to fight cancer in a patient. In other treatments, the patient’s T-cells are generally withdrawn, modified and then injected.

“It opens up the next set of options where you could in theory have these [prepared t- cells] ready for leukemia” treatment, said Dr. Madan Jagasia, Outpatient Stem Cell Transplant Program at Vanderbilt-Ingram Cancer Center. “What’s happening [now] is you’re wasting several weeks to reprogram T-cells” from the original patient.